The EU has since decided that details of all farming subsidy payments should be publicly available.

Figures available on the UK Government’s searchable database, cap-payments.defra.gov.uk, show that Brecon and Radnorshire AM Ms Williams’ family firm DC Rees and Son of Brecon received a total of £60,594.21 in EU subsidies between October 2013 and October 2014.

Many 'won't be prepared to gamble with subsidies'

Subsidy payments for the year to October 2015 are due to be published before the end of May 2016.

A pro-EU Welsh Conservative source said: “Andrew RT Davies’ family business is benefiting to the extent of almost £100,000 a year from European Commission subsidies, yet he wants Wales and the UK to leave the EU.

David Cameron has taken the opposite stance on the EU to Welsh Tory leader Andrew RT Davies (Image: Matthew Horwood)

"There is absolutely no guarantee that the same level of subsidies would be available from the UK Government if voters decide in the referendum that we should come out of the EU. Nor, as the Prime Minister pointed out at the Welsh Conservative conference in Llangollen last week , can Welsh farmers expect to avoid tariff barriers if we leave the Single Market.

"Andrew RT Davies may feel like gambling with the subsidies he is fortunate enough to receive from the EU, but may others will not be prepared to do so. Both the unions representing farmers in Wales are backing a remain vote in the referendum, and there are very clear financial reasons for that.”

Project Fear descends 'further into the gutter'

A source close to the Welsh Conservative leader responded: “This clearly shows what a principled stand Andrew is taking and he will continue to speak up for the UK and for Welsh agriculture.

"But let’s clear up one myth: there is no such thing as EU money. That money belongs to UK taxpayers and we pay £10bn a year more than we receive to be part of this racket. This attack on the man, not the ball, emphasises the lack of a positive case for staying in the EU. It seems that Project Fear just descended further into the gutter.”

Taking a risk 'to woo a few Ukip voters'

A spokesman for the Welsh Liberal Democrats said: “Wales’ farming industry is a major part of our economy and of course the European Union is tremendously important to that industry.

“Alongside farming subsidies, being in the EU is also about having access to the European market. Wales sells huge amounts of our world class produce to Europe, therefore Andrew Davies needs to explain how on earth he can guarantee that our farmers would still have access to that market.

"The Prime Minister, his party leader, has said it’s unlikely the UK Government would make up Wales’ shortfall in EU support. That would be disastrous for Wales. Yet still Andrew Davies wants to take that risk in order to woo a few Ukip voters.

“The Tories are in complete disarray. They seem determined to repeat history and tear themselves apart over the EU. The Liberal Democrats are the only UK party completely united around the case to remain. Of course we recognise that the EU is not perfect; neither is Westminster. But picking up your ball in a sulk and heading home is not the way to change our communities for the better.”